scholarly journals Photosynthetic Daily Light Integral During Root Development Influences Subsequent Growth and Development of Several Herbaceous Annual Bedding Plants

HortScience ◽  
2012 ◽  
Vol 47 (7) ◽  
pp. 856-860 ◽  
Author(s):  
Veronica A. Hutchinson ◽  
Christopher J. Currey ◽  
Roberto G. Lopez
Keyword(s):  
Growth And Development ◽  
Early Spring ◽  
Residual Effects ◽  
Late Winter ◽  
Subsequent Growth ◽  
Open Flower ◽  
Bedding Plants ◽  
Daily Light Integral ◽  
Northern Latitudes ◽  
Light Integral

Vegetatively propagated bedding plants are produced during the late winter and early spring when outdoor photosynthetic daily light integral (DLI) is low, especially in northern latitudes. Our objective was to quantify how propagation DLI influences subsequent growth and development of annual bedding plants. Cuttings of Angelonia angustifolia Benth. ‘AngelMist White Cloud’, Nemesia fruticans (Thunb.) Benth. ‘Aromatica Royal’, Osteospermum ecklonis (DC.) Norl. ‘Voltage Yellow’, and Verbena ×hybrida Ruiz ‘Aztec Violet’ were harvested and propagated in a glass-glazed greenhouse. After callusing (≈5 mol·m−2·d−1 for 7 days), cuttings of each species were placed under one of three different fixed-woven shadecloths providing ≈38%, 61%, or 86% shade or no shade with 16 h of supplemental light for 14 days. Rooted cuttings were then transplanted into 11-cm containers and grown in a common greenhouse of 21 ± 1 °C and DLI of ≈12 mol·m−2·d−1 to identify any residual effects on subsequent growth and development during the finish stage. As DLI during propagation increased, time to first open flower decreased for Angelonia, Nemesia, Osteospermum, and Verbena. For example, time to flower for Angelonia and Osteospermum was hastened by 23 and 19 days, respectively, as DLI during propagation increased from 1.2 to 12.3 mol·m−2·d−1. Our research can be used to predict growth and flowering under varying propagation DLIs for the cultivars of Angelonia, Nemesia, Osteospermum, and Verbena in the study.

scholarly journals Photosynthetic Daily Light Integral During the Seedling Stage Influences Subsequent Growth and Flowering of Celosia, Impatiens, Salvia, Tagetes, and Viola

HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1099C-1099
Author(s):  
Lee Ann Pramuk ◽  
Erik S. Runkle
Keyword(s):  
Growth And Development ◽  
Dry Weight ◽  
Seedling Stage ◽  
Residual Effects ◽  
Subsequent Growth ◽  
Flower Bud ◽  
Common Environment ◽  
Daily Light Integral ◽  
Shoot Dry Weight ◽  
Light Integral

The photosynthetic daily light integral (DLI) dramatically increases during the spring, but effects of DLI on seedling growth and development have not been characterized for many species. We quantified the effects of DLI on growth and development of Celosia, Impatiens, Salvia, Tagetes, and Viola during the seedling stage and determined whether there were any residual effects of DLI on subsequent growth and development after transplant. Seedlings were grown in growth chambers for 18–26 days at 21 °C with a DLI ranging from 4.1–14.2 mol·mol·m-2·d-1. Average seedling shoot dry weight per internode (a measure of quality) increased linearly 64%, 47%, 64%, and 68% within this DLI range in Celosia, Impatiens, Tagetes, and Viola, respectively. Seedlings were then transplanted to 10-cm containers and grown in a common environment (average daily temperature of 22 °C and DLI of 8.5 mol·m-2·d-1) to determine subsequent effects on plant growth and development. Flowering of Celosia, Impatiens, Salvia, Tagetes, and Viola occurred 10, 12, 11, 4, and 12 days earlier, respectively, when seedlings were previously grown under the highest DLI compared with the lowest. Except for Viola, earlier flowering corresponded with the development of fewer nodes below the first flower. Flower bud number and plant shoot dry weight at first flowering decreased as the seedling DLI increased in all species except for flower number of Tagetes. Therefore, seedlings grown under a greater DLI flowered earlier, but plant quality at first flowering was generally reduced compared with that of seedlings grown under a lower DLI.

scholarly journals Photosynthetic Daily Light Integral during Propagation Influences Rooting and Growth of Cuttings and Subsequent Development of New Guinea Impatiens and Petunia

HortScience ◽  
2008 ◽  
Vol 43 (7) ◽  
pp. 2052-2059 ◽  
Author(s):  
Roberto G. Lopez ◽  
Erik S. Runkle
Keyword(s):  
Growth And Development ◽  
Subsequent Development ◽  
New Guinea ◽  
Separate Experiment ◽  
Subsequent Growth ◽  
Shoot Height ◽  
Daily Light Integral ◽  
Subsequent Time ◽  
New Guinea Impatiens ◽  
Light Integral

A majority of commercial propagation of herbaceous ornamental cuttings occurs during the winter when the photosynthetic daily light integral (DLI) is relatively low. We quantified how the mean DLI influenced rooting and subsequent growth and development of two popular vegetatively propagated species, New Guinea impatiens (Impatiens hawkeri Bull.) and petunia (Petunia ×hybrida hort. Vilm.-Andr.). Three cultivars of each species were propagated under a mean DLI ranging from 1.2 to 10.7 mol·m−2·d−1. Cuttings were rooted in a controlled greenhouse environment maintained at 24 to 25 °C with overhead mist, a vapor-pressure deficit of 0.3 kPa, and a 12-h photoperiod. Rooting and growth evaluations of cuttings were made after 8 to 16 d. In a separate experiment, rooted cuttings under DLI treatments were then transplanted into 10-cm containers and grown in a common greenhouse at 21 ± 2 °C under a 16-h photoperiod to identify any residual effects on subsequent growth and development. In both species, rooting, biomass accumulation, and quality of cuttings increased and subsequent time to flower generally decreased as mean propagation DLI increased. For example, root number of petunia ‘Tiny Tunia Violet Ice’ after 16 days of propagation increased from 17 to 40 as the propagation DLI increased from 1.2 to 7.5 mol·m−2·d−1. In addition, cutting shoot height decreased from 6.3 to 4.5 cm, and root and shoot dry biomass of cuttings harvested after 16 days of propagation increased by 737% and 106%, respectively. Subsequent time to flower for ‘Tiny Tunia Violet Ice’ from the beginning of propagation decreased from 50 to 29 days as propagation DLI increased from 1.4 to 10.7 mol·m−2·d−1 regardless of the DLI provided after propagation. In New Guinea impatiens ‘Harmony White’, root and shoot dry weight of cuttings increased by 1038% and 82%, respectively, and subsequent time to flower decreased from 85 to 70 days as the propagation DLI increased from 1.2 to 10.7 mol·m−2·d−1. These experiments quantify the role of the photosynthetic DLI during propagation on the rooting and subsequent growth and development of vegetatively propagated herbaceous ornamental cuttings.

scholarly journals Photosynthetic Daily Light Integral During the Seedling Stage Influences Subsequent Growth and Flowering of Celosia, Impatiens, Salvia, Tagetes, and Viola

HortScience ◽  
2005 ◽  
Vol 40 (5) ◽  
pp. 1336-1339 ◽  
Author(s):  
Lee Ann Pramuk ◽  
Erik S. Runkle
Keyword(s):  
Growth And Development ◽  
Dry Weight ◽  
Seedling Stage ◽  
Plant Quality ◽  
Flowering Plant ◽  
Subsequent Growth ◽  
Daily Light Integral ◽  
Shoot Dry Weight ◽  
Bedding Plant ◽  
Light Integral

The photosynthetic daily light integral (DLI) dramatically increases during the spring when the majority of bedding plants are commercially produced. However, the effects of DLI on seedling growth and development have not been well characterized for most bedding plant species. Our objectives were to quantify the effects of DLI on growth and development of Celosia, Impatiens, Salvia, Tagetes, and Viola during the seedling stage and determine whether there were any residual effects of DLI on subsequent growth and development after transplant. Seedlings were grown in growth chambers for 18 to 26 days at 21 °C with a DLI ranging from 4.1 to 14.2 mol·m–2·d–1. Average seedling shoot dry weight per internode (a measure of quality) increased linearly 64%, 47%, 64%, and 68% within this DLI range in Celosia, Impatiens, Tagetes, and Viola, respectively. Seedlings were then transplanted to 10-cm containers and grown in a common environment (average daily temperature of 22 °C and DLI of 8.5 mol·m–2·d–1) to determine subsequent effects on plant growth and development. Flowering of Celosia, Impatiens, Salvia, Tagetes, and Viola occurred 10, 12, 11, 4, and 12 days earlier, respectively, when seedlings were previously grown under the highest DLI compared with the lowest. Except for Viola, earlier flowering corresponded with the development of fewer nodes below the first flower. Flower bud number and plant shoot dry weight at first flowering (plant quality parameters) decreased as the seedling DLI increased in all species except for flower number of Tagetes. Therefore, seedlings grown under a greater DLI flowered earlier, but plant quality at first flowering was generally reduced compared with that of seedlings grown under a lower DLI.

scholarly journals High Tunnel versus Climate-controlled Greenhouse: Transplant Time and Production Environment Impact Growth and Morphology of Cold-tolerant Bedding Plants

HortScience ◽  
2015 ◽  
Vol 50 (6) ◽  
pp. 830-838 ◽  
Author(s):  
Joshua R. Gerovac ◽  
Roberto G. Lopez ◽  
Neil S. Mattson
Keyword(s):  
Plant Production ◽  
Late Winter ◽  
Production Environment ◽  
Environment Impact ◽  
Open Flower ◽  
Bedding Plants ◽  
Northern Latitude ◽  
Northern Latitudes ◽  
Bedding Plant ◽  
Cold Tolerant

Commercial bedding plant production in northern latitudes often begins in late winter and continues through spring, when average outdoor temperatures require growers to actively heat their greenhouses (GHs). High tunnels (HTs) offer energy savings as they are passively heated and cooled structures that have a low initial cost. As a result, they have been used in northern latitudes to advance and extend the growing season and improve the quality of high-value horticultural crops. However, there is limited published information on growing bedding plants in HTs in northern latitudes. Our objectives were to quantify the effects of transplant date in an HT with or without a rowcover (RC) compared with a traditional heated GH on the growth and morphology of three cold-tolerant bedding plant species at two northern latitude locations, Purdue University (Purdue) and Cornell University (Cornell). Seedlings of snapdragon (Antirrhinum majus L. ‘Liberty Classic Yellow’), dianthus (Dianthus chinensis L. ‘Telstar Crimson’), and petunia (Petunia ×hybrida Vilm.-Andr. ‘Wave Pink’) were transplanted on weeks 13, 14, and 15 in 2012 (Purdue) and 2013 (both locations) and moved to either a glass-glazed GH or an HT without (HT) or with a rowcover (HT+RC). Several quality measurements increased when plants were grown in the HT compared with those grown in the GH. Dianthus and petunia transplanted at Purdue during week 13 in the HT and HT+RC were 33% and 47% shorter and had 51% and 31% more visible buds, respectively, compared with those grown in the GH. Similarly, petunia transplanted at Cornell during week 13 in the HT and HT+RC were 45% and 43% shorter, respectively, than their GH counterparts. The shoot dry mass of dianthus and snapdragon at Purdue was significantly higher when grown in the HT compared with the GH, regardless of transplant week or the use of RC likely because of increased daily light integral (DLI) in the HT environment. There was about a 1-week delay from transplant to first open flower for week 13 dianthus (at Purdue) and petunia (at both locations) when finished in the HT or HT+RC vs. their GH counterparts. Such a delay would be acceptable to growers who want to reduce the use of chemical growth regulators and heating costs. However, at both locations snapdragon transplanted on week 13 to the HT or HT+RC environments were delayed by 22 to 26 days compared with the GH. A delay of over 3 weeks could interfere with a grower’s production schedule, possibly making this crop unsuitable for production in northern latitude HTs.

scholarly journals Changes in vitamin-D metabolites and parathyroid hormone in plasma following cholecalciferol administration to pre- and postmenopausal women in the Netherlands in early spring and to postmenopausal women in Curaçao

1996 ◽  
Vol 75 (4) ◽  
pp. 637-646 ◽  
Author(s):  
Fiona R. M. Van Der Klis ◽  
Jan H. P. Jonxis ◽  
Jasper J. Van Doormaal ◽  
Peter Sikkens ◽  
Alejandro E. C. Saleh ◽  
...  
Keyword(s):  
Parathyroid Hormone ◽  
The Netherlands ◽  
Postmenopausal Women ◽  
White Women ◽  
Early Spring ◽  
Late Winter ◽  
Vitamin D Metabolites ◽  
Black And White ◽  
Northern Latitudes ◽  
The Tropics

To study the effect on plasma 25-hydroxycholecalciferol (25(OH)D), 1,25-dihydroxycholecalciferol (1,25(OH)2D) and parathyroid hormone (PTH) we supplemented premenopausal (aged 30 (SD 7) years) and postmenopausal (aged 61 (SD 2) years) white women living in The Netherlands in late winter/early spring, and elderly black and white women (aged 75 (SD 6) years) living in Curacao (Dutch Antilles) with either 10 or 20µpg cholecalciferol/d for 4, 5 and 9 weeks respectively. Baseline plasma 25(OH)D concentration of Dutch women was lower than that of Curacao women. Postmenopausal Dutch women had a higher PTH concentration in plasma than premenopausal Dutch and postmenopausal Curaçao women. There were no differences in plasma 1,25(OH)2D. Cholecalciferol administration increased 25(OH)D in all groups, 1,25(OH)2D in postmenopausal Curaçao women and PTH in postmenopausal Curaçao women and premenopausal Dutch women. Serum and urinary Ca and phosphate concentrations did not change. There were no response differences between 10 and 20 µg doses. Oral cholecalciferol administration (either 10 or 20 µg/d) to women living at northern latitudes in late winter/early spring increased 25(OH)D levels to the baseline levels of elderly people living in the tropics.

scholarly journals Strawberry Growth and Development in an Annual Plasticulture System

HortScience ◽  
2001 ◽  
Vol 36 (7) ◽  
pp. 1219-1223 ◽  
Author(s):  
Gina E. Fernandez ◽  
Laura M. Butler ◽  
Frank J. Louws
Keyword(s):  
Resource Allocation ◽  
Growth And Development ◽  
Dry Matter ◽  
Transition Period ◽  
Early Spring ◽  
Dry Matter Production ◽  
Late Winter ◽  
Dry Matter Accumulation ◽  
Plant Parts ◽  
Matter Production

The growth and development of three strawberry cultivars commonly grown in a plasticulture system were documented. Strawberry plants were harvested monthly and divided by roots, crown, leaves, flowers, and fruit and then dried in an oven. The dry matter production and resource allocation proceeded along a predictable pattern of development. The establishment phase was characterized by an active period of growth of root, crown and leaves in the fall. Through the winter, the plants underwent slow growth, ending in a transition period in the late winter/early spring when resources were allocated to both vegetative and reproductive growth. In the spring, all plant parts received significantly increased allocation of, or redistribution of, resources. Cultivars of California origin, `Chandler' and `Camarosa', displayed similar trends in yield, dry matter production, seasonal resource allocation, and growth analysis variables throughout the season. `Sweet Charlie', a cultivar from Florida, showed lower dry matter accumulation and relative growth rate in the spring, higher harvest index and lower yield than the California cultivars.

scholarly journals Photosynthetic Daily Light Integral during Propagation of Tecoma stans Influences Seedling Rooting and Growth

HortScience ◽  
2011 ◽  
Vol 46 (2) ◽  
pp. 282-286 ◽  
Author(s):  
Ariana P. Torres ◽  
Roberto G. Lopez
Keyword(s):  
Leaf Area ◽  
Dry Mass ◽  
Early Spring ◽  
Node Number ◽  
Tropical Plants ◽  
Daily Light Integral ◽  
Tropical Plant ◽  
Increasing Demand ◽  
Seed Propagation ◽  
Light Integral

Current market trends indicate an increasing demand for unique and exotic flowering crops, including tropical plants. Tecoma stans (L. Juss. Kunth) ‘Mayan Gold’ is a tropical plant that was selected as a potential new greenhouse crop for its physical appearance and drought and heat tolerance. However, in winter and early spring, when propagation occurs, outdoor photosynthetic daily light integral (DLI) can be relatively low. The objective of this study was to quantify the effects of DLI during propagation of Tecoma and to determine optimum DLI levels for seed propagation. Seeds were propagated under 13 mean DLIs ranging from 0.75 to 25.2 mol·m−2·d−1 created by the combination of high-pressure sodium lamps (HPS) and fixed woven shadecloths of varying densities. Thirty-five days after sowing, height, stem diameter, node number, relative leaf chlorophyll content, leaf fresh weight, leaf number, total leaf area, individual leaf area, leaf area ratio, shoot and root dry mass increased as DLI increased. Average internode elongation and specific leaf area decreased at a quadratic and linear rate, respectively, as DLI increased from 0.75 to 25.2 mol·m−2·d−1. These experiments indicate that high-quality Tecoma seedlings were obtained when DLI was 14 to 16 mol·m−2·d−1 during propagation.

scholarly journals Modeling Growth and Development of Celosia and Impatiens in Response to Temperature and Photosynthetic Daily Light Integral

2005 ◽  
Vol 130 (6) ◽  
pp. 813-818 ◽  
Author(s):  
Lee Ann Pramuk ◽  
Erik S. Runkle
Keyword(s):  
Flowering Time ◽  
Economic Value ◽  
Dry Mass ◽  
Early Summer ◽  
Flower Bud ◽  
Bedding Plants ◽  
Daily Light Integral ◽  
Wide Range ◽  
Greenhouse Growers ◽  
Light Integral

Commercial greenhouse growers often produce bedding plants from midwinter to early summer, and thus crops are grown under a wide range of environmental conditions. Despite bedding plants' high economic value, the interactions of temperature and photosynthetic daily light integral (DLI) on growth and flowering have not been determined for many bedding plants. We grew celosia (Celosia argentea L. var. plumosa L.) and seed impatiens (Impatiens wallerana Hook.f.) in glass greenhouses in a range of temperature (15 to 27 °C) and DLI (8 to 26 mol·m-2·d-1) conditions to quantify effects on growth and flowering. Growth (e.g., plant dry mass at flowering) and flowering characteristics (e.g., time to flowering and flower bud number) were modeled in response to the average daily temperature and DLI by using multiple regression analysis. Rate of progress to flowering (1/days to flower) of celosia increased as temperature increased up to ≈25 °C and as the average DLI increased to 15 ·mol·m-2·d-1. Impatiens grown under a DLI <15 mol·m-2·d-1 flowered progressively earlier as temperature increased from 14 to 28 °C, whereas temperature had little effect on flowering time when plants were grown under the highest DLI treatments. Number of flowers and flower buds at first flowering increased in both species as temperature decreased or DLI increased. Shoot dry mass at first flowering followed a similar trend, except celosia dry mass decreased as temperature decreased. The models developed to predict flowering time and plant quality could be used by commercial growers to determine the impacts of changing growing temperature, growing plants at different times of the year, and providing supplemental lighting.

scholarly journals Promotion of Flowering from Far-red Radiation Depends on the Photosynthetic Daily Light Integral

HortScience ◽  
2018 ◽  
Vol 53 (4) ◽  
pp. 465-471 ◽  
Author(s):  
W. Garrett Owen ◽  
Qingwu Meng ◽  
Roberto G. Lopez
Keyword(s):  
Plant Height ◽  
Open Flower ◽  
Led Lighting ◽  
Daily Light Integral ◽  
Low Intensity ◽  
Short Day ◽  
Long Day ◽  
Long Day Plants ◽  
African Marigold ◽  
Light Integral

Under natural short days, growers can use photoperiodic lighting to promote flowering of long-day plants and inhibit flowering of short-day plants. Unlike traditional lamps used for photoperiodic lighting, low-intensity light-emitting diode (LED) lamps allow for a wide array of adjustable spectral distributions relevant to regulation of flowering, including red (R) and white (W) radiation with or without far-red (FR) radiation. Our objective was to quantify how day-extension (DE) photoperiodic lighting from two commercially available low-intensity LED lamps emitting R + W or R + W + FR radiation interacted with daily light integral (DLI) to influence stem elongation and flowering of several ornamental species. Long-day plants [petunia (Petunia ×hybrida Vilm.-Andr. ‘Dreams Midnight’) and snapdragon (Antirrhinum majus L. ‘Oh Snap Pink’)], short-day plants [african marigold (Tagetes erecta L. ‘Moonsong Deep Orange’) and potted sunflower (Helianthus annuus L. ‘Pacino Gold’)], and day-neutral plants [pansy (Viola ×wittrockiana Gams. ‘Matrix Yellow’) and zinnia (Zinnia elegans Jacq. ‘Magellan Cherry’)] were grown at 20/18 °C day/night air temperatures and under low (6–9 mol·m−2·d−1) or high (16–19 mol·m−2·d−1) seasonal photosynthetic DLIs from ambient solar radiation combined with supplemental high-pressure sodium lighting and DE LED lighting. Photoperiods consisted of a truncated 9-hour day (0800–1700 hr) with additional 1-hour (1700–1800 hr, 10 hours total), 4-hour (1700–2100 hr, 13 hours total), or 7-hour (1700–2400 hr, 16 hours total) R + W or R + W + FR LED lighting at 2 μmol·m−2·s−1. Days to visible bud, plant height at first open flower, and time to first open flower (TTF) of each species were influenced by DLI, lamp type, and photoperiod though to different magnitudes. For example, plant height of african marigold and potted sunflower at first open flower was greatest under R + W + FR lamps, high DLIs, and 16-hour photoperiods. Petunia grown under R + W lamps, high DLI, and 10- and 13-hour photoperiods were the most compact. For all species, TTF was generally reduced under high DLIs. For example, regardless of the lamp type, flowering of african marigold occurred fastest under a high DLI and 10-hour photoperiod. Flowering of petunia and snapdragon occurred fastest under a high DLI, R + W + FR lamps, and a 16-hour photoperiod. However, only under high DLIs, R + W or R + W + FR lamps were equally effective at promoting flowering when used to provide DE lighting. Our data suggest that under low DLIs, flowering of long-day plants (petunia and snapdragon) occurs more rapidly under lamps providing R + W + FR, whereas under high DLIs, flowering is promoted similarly under either R + W or R + W + FR lamps.

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